1. Field of the Invention
The present invention relates to a vehicle-mounted engine control system and method for an internal combustion engine, in which the system includes a control unit and an inclination sensor for detecting a vehicle body inclination.
2. Description of the Background Art
The applicant of the present invention previously filed an application for a patent, JP-A No. 68062/2002, to disclose a motorcycle-mounted internal combustion engine controller that includes an inclination sensor for detecting a vehicle body inclination.
The controller disclosed in JP-A No. 68062/2002 includes an inclination sensor. A plumb bob is suspended within a case, which is integral with a vehicle body, and allowed to swing from right to left and vice versa. The inclination sensor detects a vehicle body inclination by determining a relative angle that is formed between the plumb bob, which constantly indicates verticality, and the case, which inclines together with the vehicle body. The controller stops the operation of the internal combustion engine when a predetermined period of time is exceeded by the period during which a vehicle body inclination angle detected by the inclination sensor is greater than a predetermined angle.
When, for instance, the vehicle body repeatedly inclines, the plumb bob may temporarily swing from the vertical. Therefore, the inclination sensor may erroneously detect an undue vehicle body inclination that is greater than the actual one. When such erroneous detection of vehicle body inclination occurs, there is no need to stop the internal combustion engine.
The above-mentioned erroneous vehicle body inclination detection is temporary. The internal combustion engine is stopped only when a vehicle body inclination is continuously detected for a certain period of time. Therefore, the internal combustion engine does not stop in the event of an erroneous or short-term temporary vehicle body inclination detection.
Although the known devices have some utility for their intended purposes, a need still exists in the art for a vehicle control system having an improved threshold stop time setting. The threshold stop time setting of the previously known system, which defines the vehicle body inclination period, is constant no matter what operational state the internal combustion engine is in. Therefore, the threshold stop time setting defined in JP-A No. 68062/2002 may unexpectedly stop the operation of the internal combustion engine depending on its operational state.